The invention relates to the field of fastening devices for tubing. In particular, the invention relates to plumbing fastening devices which can be slipped over and around a pre-formed shoulder of a sealing surface on a tube and engage a mating receptacle, to effect a substantially leak-proof connection of the tube.
In the plumbing art, it is often necessary to connect two plumbing tubes together in end-to-end fashion or to connect a plumbing tube to a receptacle. The connections have typically been made by employing an internally threaded nut on one tube and a mating externally threaded receiving device on the other tube (or on the receptacle). However, a plumbing tube often has a connecting end that includes a sealing surface. The sealing surface is usually an enlarged area that provides greater surface contact to reduce or eliminate any leaks that may occur at the plumbing connection. For example, as shown in FIG. 1, a connector of the prior art 10 includes a tube 12 with an enlarged sealing surface 14.
In effecting sealing engagement, an internally threaded nut 16 connects to a mating externally threaded receptacle (not shown). This type of connection suffers from the fact that nut 16 must be inserted onto tube 12 prior to the formation of enlarged sealing surface 14 during the production process or prior to any processing on an opposed end such as the formation of a belled end 18. Insertion of nut 16 onto tube 12 during the production process detrimentally incurs additional manufacturing time and expense. Also, the placement of nut 16 on tube 12 during manufacturing severely limits the ability of nut 16 to be replaced or installed in the field, again leading to additional time and expense to make repairs to a plumbing connection.
Moreover, threaded fasteners of the prior art require circumferential rotational movement, i.e. turning, to effect engagement, and often, the number of turns exceeds two to three times about the original starting point. Because many plumbing connections are made in areas having restricted space, it is difficult and time-consuming to turn the prior art fasteners the required number of times to effect a complete, sealed connection, if possible at all.
Accordingly, it is desirable to develop a fastener that overcomes the disadvantages of the prior art by having the ability to be inserted onto a respective tube after fabrication of the tube and requires less than a full turn to effect sealing engagement.